The present invention relates to a remote control key for remotely controlling locking and unlocking of a door, and more particularly, to a remote control key that prevents theft of a transponder incorporated in the remote control key.
Japanese Laid-Open Patent Publication No. 2002-213124 describes a prior art example of a vehicle lock that facilitates the locking and unlocking of a vehicle door. The vehicle lock is provided with a remote control key (door key), which includes a transmitter and a transponder. When a lock/unlock button (operation button) of the remote control key is operated, the transmitter transmits a stored ID code. The transponder receives a transponder drive signal from the vehicle and transmits a transponder signal for starting the engine. When receiving the ID code from the remote control key, the vehicle compares the ID code with a stored ID code. If the two ID codes match, the vehicle locks or unlocks the doors. Further, when an ID code included in the transponder signal transmitted from the transponder matches the ID code of the vehicle, the vehicle starts the engine.
Japanese Laid-Open Patent Publication No. 9-105255 describes an example of such a remote control key (ignition key) that separately incorporates a transmitter and a transponder. The remote control key uses electromagnetic energy, which is supplied from the vehicle, to transmit an ID code. Another proposed type of remote control key incorporates a battery to drive a transmitter. The battery generates power and reduces power consumption in the vehicle.
A further proposed type of a remote control key incorporates a transmitter and a transponder, which are formed integrally with each other to reduce the manufacturing steps and manufacturing cost of the remote control key.
It is preferable that the remote control key be easily disassembled to facilitate maintenance, such as replacement of a battery or a transponder. However, when the disassembly of a remote control key is easy, a third person may disassemble the remote control key and remove the transponder. In addition, even if the transponder is removed, the removal of the transponder is not readily noticeable since it is light. Thus, when the remote control key may easily be disassembled, this may lower the security level of the vehicle.
To prevent removal of the transponder, an adhesive agent or the like may be used to make disassembly of the remote control key difficult. However, this would cause difficulties in maintenance for the transmitter of the remote control key.